Samsung S3F80JB manual JP Jump, Labelw

Models: S3F80JB

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S3F80JBINSTRUCTION SET

JP — Jump

JP

cc,dst

(Conditional)

JP

dst

(Unconditional)

Operation:

If cc

is true, PC dst

The conditional JUMP instruction transfers program control to the destination address if the condition specified by the condition code (cc) is true; otherwise, the instruction following the JP instruction is executed. The unconditional JP simply replaces the contents of the PC with the contents of the specified register pair. Control then passes to the statement addressed by the PC.

Flags: No flags are affected.

Format: (1)

(2)

cc opc

dst

Bytes

Cycles

Opcode

Addr Mode

 

 

(Hex)

dst

3

8

ccD

DA

 

 

cc = 0 to F

 

opc

dst

2 8 30 IRR

NOTES:

1.The 3-byte format is used for a conditional jump and the 2-byte format for an unconditional jump.

2.In the first byte of the three-byte instruction format (conditional jump), the condition code and the opcode are both four bits.

Examples: Given: The carry flag (C) = "1", register 00 = 01H, and register 01 = 20H:

JP

C,LABEL_W

LABEL_W = 1000H, PC = 1000H

JP

@00H

PC = 0120H

The first example shows a conditional JP. Assuming that the carry flag is set to "1", the statement "JP C,LABEL_W" replaces the contents of the PC with the value 1000H and transfers control to that location. Had the carry flag not been set, control would then have passed to the statement immediately following the JP instruction.

The second example shows an unconditional JP. The statement "JP @00" replaces the contents of the PC with the contents of the register pair 00H and 01H, leaving the value 0120H.

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Page 175
Image 175
Samsung S3F80JB manual JP Jump, Labelw